Solid titanium catalyst component and its use in olefin polymerization catalyst

ABSTRACT

The invention provides a process for preparing a solid titanium catalyst component for use in the preparation of an olefin polymerization catalyst, which comprises: 
     (1) a step wherein a suspension is prepared which contains a solid material prepared by contacting a magnesium compound with a first titanium compound and having a polybasic carboxylic acid ester supported thereon; 
     (2) a step wherein the solid material is separated from the suspension; and 
     (3) a step wherein the solid material is contacted with a second titanium compound under heating; 
     wherein while the solid material is separated from the suspension in the step (2) and the solid material is supplied to the step (3), the solid material is maintained at a temperature in the range of 70-130° C.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a solid titanium catalyst component and anolefin polymerization catalyst prepared from the same. Moreparticularly, the invention relates to a process for preparing a solidtitanium catalyst component, such a catalyst component as prepared bythe process, a preliminary olefin polymerization catalyst and an olefinpolymerization catalyst both prepared from such a catalyst component,and a process for producing polyolefins using such catalysts.

2. Description of the Prior Art

A Ziegler-Natta catalyst comprising a titanium catalyst component and anorganoaluminum compound have been in wide use as an olefinpolymerization catalyst. It is already known that a catalyst which isprepared from a solid titanium catalyst component comprising a titaniumcompound supported on a solid carrier has high polymerization activity.In particular, it is also known that a catalyst which is prepared from asolid titanium catalyst component comprising a titanium compoundsupported on a solid halogenated magnesium compound has highpolymerization activity, but also the catalyst provides highlystereospecific polyolefins in high yields when it is used for thepolymerization of alpha-olefins having at least three carbon atoms suchas propylene or 1-butene.

The solid titanium catalyst component comprising a titanium compoundsupported on a solid halogenated magnesium compound may be prepared bycontacting a halogenated magnesium compound, a titanium compound and anelectron donor with each other.

A process for an olefin polymerization using such a solid titaniumcatalyst component is known, as disclosed in Japanese Patent ApplicationLaid-open No. 58-83006. According to the prior art, a solid titaniumcatalyst component is prepared by use of a hydrocarbon solution of amagnesium compound, a titanium compound which is per se liquid such astitanium tetrachloride and an electron donor. An olefin polymerizationcatalyst is then prepared from the solid titanium catalyst component, anorganometallic catalyst component and an organosilicone catalystcomponent. The prior art uses a certain compound such as an acidanhydride in combination with a polybasic carboxylic acid ester or apolyhydric alcohol ester as an electron donor when the solid titaniumcatalyst component is prepared.

The hydrocarbon solution of a magnesium compound is prepared usually bysolubilizing a magnesium compound which is solid at normal temperaturessuch as magnesium chloride with a solubilizing agent, if necessary, in ahydrocarbon solvent. A preferred example of the solubilizing agent is analcohol such as 2-ethylhexanol.

More specifically, according to the prior art, the solid titaniumcatalyst component is prepared by first contacting a solution of amagnesium compound with titanium tetrachloride in the presence of anelectron donor to form a suspension which contains the resultant solidmaterial; the solid material is separated from the suspension; and thenthe solid material is again contacted with titanium tetrachloride underheating.

As mentioned above, the polymerization of olefins in the presence of acatalyst prepared from the solid titanium catalyst component togetherwith an organometallic catalyst component and an organosilicone catalystcomponent provides polyolefins in high yields. In particular, thepolymerization of alpha-olefins having at least three carbon atomsprovides highly stereospecific polyolefins in high yields. In addition,the resulting polyoefins have a small content of finely divided polymerpowder as well as narrow particle distribution and high bulk density.

The known olefin polymerization catalyst which is prepared by a methodas described above and contains the solid titanium catalyst componenthas a high performance in many respects, that is, in respect ofpolymerization activity, and stereospecificity and particle propertiesof the resulting polymers, as above set forth. However, in recent years,there is a strong demand for a solid titanium catalyst component for usein the preparation of an olefin polymerization catalyst which reducesthe amount of finely divided polymer powder produced.

Therefore, it is an object of the invention to provide a solid titaniumcatalyst component for use in an olefin polymerization catalyst whichhas high olefin polymerization activity, and in particular, for use inan alpha-olefin polymerization catalyst which provides polyolefinshaving high stereospecificity and bulk density in high yields with areduced amount of finely divided polymer powder produced whenalpha-olefins having at least three carbon atoms are polymerized.

It is a further object of the invention to provide such a solid titaniumcatalyst component, a preliminary olefin polymerization catalyst and anolefin polymerization catalyst both comprising the solid titaniumcatalyst component and a process for the polymerization of olefins usingsuch catalysts.

SUMMARY OF THE INVENTION

The invention provides a process for preparing a solid titanium catalystcomponent which comprises:

(1) a step wherein a suspension is prepared which contains a solidmaterial prepared by contacting a magnesium compound with a firsttitanium compound and having a polybasic carboxylic acid ester supportedthereon;

(2) a step wherein the solid material is separated from the suspension;and

(3) a step wherein the solid material is contacted with a secondtitanium compound under heating;

wherein while the solid material is separated from the suspension in thestep (2) and the solid material is supplied to the step (3), the solidmaterial is maintained at a temperature in the range of 70-130° C.

The invention further provides an olefin polymerization catalyst whichcomprises:

(A) the solid titanium catalyst component as prepared by the process asmentioned above;

(B) an organometallic compound; and

(C) a silane compound having Si—O—C bond in the molecule.

The invention also provides a preliminary olefin polymerization catalystwhich is prepared by polymerizing an olefin or two or more olefins inthe presence of catalyst components comprising:

(A) the solid titanium catalyst component as prepared by the process asmentioned above;

(B) an organometallic compound; and optionally

(C) a silane compound having Si—O—C bond in the molecule.

The invention still further provides a process for the polymerization ofolefins which comprises polymerizing an olefin or copolymerizing two ormore olefins in the presence of the olefin polymerization catalyst asmentioned above.

According to the invention, there is further provided a process for thepolymerization of olefins which comprises polymerizing an olefin orcopolymerizing two or more olefins in the presence of a polymerizationcatalyst which comprises:

the above mentioned preliminary olefin polymerization catalyst, andoptionally

(B) an organometallic compound and/or

(C) a silane compound having Si—O—C bond in the molecule.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the steps for preparation of solid titanium catalystcomponent and for the polymerization of olefins according to theinvention; and

FIG. 2 shows an example of arrangement of apparatus for the preparationof solid titanium catalyst component of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preparation of the solid titanium catalyst component of theinvention will be first described. As illustrated in FIG. 1, the solidtitanium catalyst component is prepared by carrying out the followingsteps:

(1) a step wherein a suspension is prepared which contains a solidmaterial prepared by contacting a magnesium compound with a firsttitanium compound and having a polybasic carboxylic acid ester supportedthereon;

(2) a step wherein the solid material is separated from the suspension;and

(3) a step wherein the solid material is contacted with a secondtitanium compound under heating;

wherein while the solid material is separated from the suspension in thestep (2) and the solid material is supplied to the step (3), the solidmaterial is maintained at a temperature in the range of 70-130° C.

(Step(1)—Magnesium Compound)

It is preferred that a magnesium compound is made into a solution and isthen contacted with a first titanium compound. When a magnesium compoundis soluble in a solvent, the magnesium compound is dissolved in thesolvent to form a solution. When a magnesium compound is prepared as asolution, for example, as in the case of a Grignard reagent, theresulting solution may be used as it is. When a magnesium compound issolubilized with a solubilizing agent, the magnesium compound may bedissolved in the solubilizing agent as a solvent. The magnesium compoundmay be dissolved in a solvent such as a hydrocarbon solvent in thepresence of the solubilizing agent.

However, when a magnesium compound is used which is solid at normaltemperatures and is not soluble in common solvents inclusive of thesolubilizing agent, the magnesium compound may be dispersed in a solventto form a suspension, and the suspension may be contacted with the firsttitanium compound.

The magnesium compound used in the invention may or may not have areducing ability. The magnesium compound having a reducing abilityincludes an organomagnesium compound which may be represented by theformula:

X_(n)M_(g)R_(2-n)

wherein n is a numeral which fulfils the condition of 0≦n<2; R is ahydrogen, or an alkyl, an aryl or a cycloalkyl of 1-20 carbons; when nis 0, the two R's may be the same or different from each other; X is ahalogen atom.

Illustrative of the magnesium compound having a reducing ability aredialkyl magnesiums such as dimethylmagnesium, diethylmagnesium,dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium,didecylmagnesium, octylbutylmagnesium or ethylbutylmagnesium; alkylmagnesium halides such as ethylmagnesium chloride, propylmagnesiumchloride, butylmagnesium chloride, hexylmagnesium chloride oramylmagnesium chloride; and alkyl magnesium alkoxides such asbutylethoxymagnesium, ethylbutoxymagnesium or octylbutoxymagnesium. Inaddition, alkyl magnesium hydrides such as butylmagnesium hydride areone of further examples of the magnesium compound having a reducingability.

In turn, illustrative of the magnesium compound having no reducingability are magnesium halides such as magnesium chloride, magnesiumbromide, magnesium iodide or magnesium fluoride; alkoxy magnesiumhalides such as methoxymagnesium chloride, ethoxymagnesium chloride,isopropoxymagnesium chloride, butoxymagnesium chloride oroctoxymagnesium chloride; aryloxy magnesium halides such asphenoxymagnesium chloride or methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium,butoxymagnesium, n-octoxymagnesium or 2-ethylhexoxymagnesium; aryloxymagnesiums such as phenoxymagnesium or dimethylphenoxymagnesium; andmagnesium carboxylates such as magnesium laurate or magnesium stearate.

Beside the above mentioned, magnesium hydride may be used as a magnesiumcompound. Metallic magnesium may also be used in place of the magnesiumcompound.

The magnesium compound having no reducing ability may be derived fromthe magnesium compound having a reducing ability or may be prepared whenthe catalyst component is prepared. In order to prepare a magnesiumcompound having no reducing ability from a magnesium compound having areducing ability, for example, the latter may be put into contact withpolysiloxane compounds, halogen-containing silane compounds,halogen-containing aluminum compounds, esters, alcohols,halogen-containing compounds, or compounds having hydroxyl groups oractive carbon-oxygen bonds in the molecule.

The magnesium compound, whether it has a reducing ability or it has not,may be in the form of complex compounds with organometallic compoundssuch as of aluminum, zinc, boron, beryllium, sodium or potassium whichwill be hereinafter mentioned, or in the form of mixtures with othermetal compounds. The magnesium compound may be used singly or as amixture of two or more.

The magnesium compound used in the invention is not limited to those asexemplified as above, however, it is preferred that the magnesiumcompound exists in the form of halogen-containing magnesium compounds inthe solid titanium catalyst component prepared. Accordingly, when amagnesium compound containing no halogens is used, it is desirable thatthe magnesium compound be contacted with a halogen-containing compoundduring the preparation process of solid titanium catalyst component.

Among the magnesium compounds mentioned above, those having no reducingability are preferred, inter alia, halogen-containing magnesiumcompounds. In particular, magnesium chloride, alkoxy magnesium chloridesor aryloxy magnesium chlorides are most preferred.

When magnesium compounds which are solid at normal temperatures areused, some of such magnesium compounds can be solubilized with asolubilizung agent in such a solubilizung agent, thereby forming asolution.

The solubilizung agent usable includes, for example, alcohols, phenols,ketones, aldehydes, ethers, amines, pyridines and metal acid esters.More specifically, the solubilizung agent may be exemplified by alcoholsof 1-18 carbons such as methanol, ethanol, propanol, butanol, pentanol,hexanol, 2-ethylhexanol, octanol, dodecanol, octadecyl alcohol, oleylalcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol orisopropylbenzyl alcohol; halogen-containing alcohols of 1-18 carbonssuch as trichloromethanol, trichloroethanol or trichlorohexanol; phenolsof 6-20 carbons which may carry lower alkyl groups as substituentsthereon such as phenol, cresol, xylenol, ethylphenol, propylphenol,nonylphenol, cumylphenol or naphthol; ketones of 3-15 carbons such asacetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl n-butylketone, acetophenone, benzophenone, benzoquinone or cyclohexanone;aldehydes of 2-15 carbons such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde or naphthoaldehyde; ethers of 2-20carbons such as methyl ether, ethyl ether, isopropyl ether, butyl ether,amyl ether, tetrahydrofuran, ethyl benzyl ether, ethylene glycol dibutylether, anisole or diphenyl ether; amines such as trimethylamine,triethylamine, tributylamine, tribenzylamine, tetramethylenediamine orhexamethylenediamine; pyridines such as pyridine, methylpyridines,ethylpyridines, propylpyridines, dimethylpyridines,ethylmethylpyridines, trimethylpyridines, phenylpyridines,benzylpyridines or chloropyridines; and metal acid esters such astetraethoxytitanium, tetra-n-propoxytitanium, -tetraisopropoxytitanium,tetrabutoxytitanium, tetrahexoxytitanium, tetraethoxyzirconium ortetrabutoxyzirconium.

Among the variety of solubilizing agents as mentioned above, alcohols ormetal acid esters are preferred, and in particular, alcohols of not lessthan 6 carbons are most preferred. In order to solubilize a magnesiumcompound with an alcohol of not less than 6 carbons, the alcohol is usedusually in an amount of not less than 1 mole part, preferably in anamount of not less than 1.5 mole parts, per mole part of magnesiumcompound. There is no specific upper limit in the amount of thesolubilizing agent used, however, it is preferred that the solubilizingagent is used in an amount of not more than 40 mole parts per mole partof the magnesium compound used from the economical stand-point. On theother hand, when a lower alcohol of not more than 5 carbons is used as asolubilizing agent to solubilize a magnesium compound, it is necessaryto use the solubilizing agent in an amount of not less than about 15mole parts per mole part of the magnesium compound used.

A solid magnesium compound is solubilized with a solubilizing agent byadmixing the magnesium compound with the agent, if necessary followed byheating the mixture. The magnesium compound is solubilized in this wayat a temperature usually in the range of 0-200° C., preferably in therange of 20-180° C., most preferably in the range of 50-150° C.

A solid magnesium compound may be dissolved in a solvent such as ahydrocarbon solvent in the presence of the solubilizing agent. Thehydrocarbon solvent includes, for example, aliphatic hydrocarbons suchas pentane, hexane, heptane, octane, decane, dodecane, tetradecane orkerosene; alicyclic hydrocarbons such as cyclopentane,methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane orcyclohexene; halogenated hydrocarbons such as dichloroethane,dichloropropane,, trichloroethylene or chlorobenzene; and aromatichydrocarbons such as benzene, toluene or xylene.

According to the invention, it is especially preferred that a magnesiumcompound, preferably a halogenated magnesium, inter alia, magnesiumchloride, is used in the form of a solution in a hydrocarbon solvent inthe presence of an alcohol as a solubilizing agent. However, it is alsopreferred that a dialkoxy magnesium such as diethoxymagnesium isdispersed in a hydrocarbon solvent and the resulting suspension is usedfor contact with the first titanium compound.

The solubilizing agent solublizes a solid magnesium compound presumablyon account of formation of complexes with the magnesium compound.However, when the lower aliphatic alcohol is used as a solubilizingagent in an insufficient amount, it may form coplexes with a magnesiumcompound, but it does not solubilizes the magnesium compound therein. Inthis case, however, it is possible to prepare a suspension whichcontains a solid material having a polybasic carboxylic acid estersupported thereon by the following process in the step (1). Namely, thelower alcohol is reacted with the magnesium compound in a hydrocarbonsolvent in the presence of a surfactant to form complexes with themagnesium compound to provide a suspension which contains the complex,and the suspension is then cooled to provide a suspension which containsa solid product, followed by supporting a polybasic carboxylic acidester thereon.

(Step (1)—First Titanium Compound)

According to the invention, a titanium compound which is tetravalent andis per se liquid at normal temperatures is preferably used as the firsttitanium compound. The first titanium compound preferably used in theinvention has the formula:

Ti(OR)_(m)X_(4-m)

wherein R is a monovalent hydrocarbon group, preferably an alkyl of 1-18carbons; X is a halogen atom, preferably a chlorine or bromine atom; mis an integer of 0-4.

The first titanium compound as mentioned above includes, for example,tetrahalogenated titaniums such as titanium tetrachloride, titaniumtetrabromide or titanium tetraiodide; trihalogenated alkoxy titaniumssuch as trichloromethoxytitanium, trichloroethoxytitanium,trichloro-n-butoxytitanium, tribromoethoxytitanium ortribromoisobutoxytitanium; dihalogenated dialkoxy titaniums such asdichlorodimethoxytitanium, dichlorodiethoxytitanium,dichlorodi-n-butoxytitanium or dibromodiethoxytitanium; monohalogenatedtrialkoxy titaniums such as chlorotrimethoxytitanium,chlorotriethoxytitanium, chlorotri-n-butoxytitanium orbromotriethoxytitanium; and tetraalkoxy titaniums such astetramethoxytitanium, tetraethoxytitanium, tetra-n-butoxytitanium,tetraisobutoxytitanium or tetra(2-ethylhexyloxy)titanium. The firsttitanium compound may be used singly or as a mixture of two or more.Among the first titanium compounds as above, a tetraalkoxy titanium ispreferred with titanium tetrachloride being most preferred.

The first titanium compound is per se liquid at normal temperatures, andmay be used as it is. However, if necessary, the first titanium compoundmay be used as a solution in a hydrocarbon solvent. The hydrocarbonsolvent includes, as mentioned hereinbefore, for example, aliphatichydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane,tetradecane or kerosene; alicyclic hydrocarbons such as cyclopentane,methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane orcyclohexene; halogenated hydrocarbons such as dichloroethane,dichloropropane, trichloroethylene-or chlorobenzene; and aromatichydrocarbons such as benzene, toluene or xylene.

The first titanium compound is used usually in an amount of 0.01-1000mole parts, preferably in an amount of 0.1-200 mole parts, per mole partof the magnesium compound used.

(Step (1)—Electron Donor)

When a magnesium compound in the form of a solution is contacted withthe first titanium compound to form a solid product, it is desirablethat the magnesium compound is contacted with the first titaniumcompound in the presence of an electron donor so that the finallyobtained solid titanium catalyst component having a uniform shape andparticle size.

The electron donor usable includes, for example, organic carboxylic acidesters preferably of 2-18 carbons such as methyl formate, methylacetate, ethyl acetate, vinyl acetate, propyl acetate, isobutyl acetate,t-butyl acetate, octyl acetate, cyclohexyl acetate, methylchloroacetate, ethyl dichloroacetate, ethyl propionate, ethyl pyruvate,ethyl pivalate, methyl butyrate, ethyl valerate, methyl methacrylate,ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethylbenzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexylbenzoate, phenyl benzoate, benzyl benzoate, methyl toluylate, ethyltoluylate, amyl toluylate, ethyl ethylbenzoate, methyl anisate, ethylanisate, ethyl ethoxybenzoate, γ-butyrolactone, δ-valerolactone,coumarin or phthalides; aliphatic carboxylic acids such as formic acid,acetic acid, propionic acid, butyric acid or valeric acid; acidanhydrides such as acetic anhydride, phthalic anhydride, maleicanhydride, benzoic anhydride, trimellitic anhydride ortetrahydrophthalic anhydride; ketones such as acetone, methyl ethylketone, methyl isobutyl ketone, ethyl n-butyl ketone, acetophenone,benzophenone, benzoquinone or cyclohexanone; ethers such as methylether, ethyl ether, isopropyl ether, butyl ether, amyl ether, ethylbenzyl ether, ethylene glycol dibutyl ether, anisole or diphenyl ether;alkoxyl group-containing alcohols such as butyl cellosolve or ethylcellosolve; aliphatic carbonates such as dimethyl carbonate, diethylcarbonate or ethylene carbonate; alkyl silicates such as methyl silicateor ethyl silicate; silane compounds such as diphenyldimethoxysilane; andorganophosphorous compounds, preferably organic phosphites, such astrimethyl phosphite or triethyl phosphite.

The electron donor may be used usually in an amount of 0.01-5 moleparts, preferably in an amount of 0.02-2 mole parts, most preferably inan amount of 0.05-1 mole parts, per mole part of the magnesium compoundused.

(Step (1)—Polybasic Carboxylic Acid Ester)

According to the invention, there is prepared in the step (1) asuspension which comprises a solid material prepared by contacting themagnesium compound with the first titanium compound and having apolybasic carboxylic acid ester supported thereon. The polybasiccarboxylic acid ester usable includes, for example, aliphatic, alicyclicand aromatic polybasic carboxylic acid esters.

The aliphatic polybasic carboxylic acid ester includes, for example,diethyl succinate, dibutyl succinate, diethyl methylsuccinate,diisopropyl α-methylglutarate, diethyl methylmalonate, diethylethylmalonate, diethyl isopropylmalonate, diethyl butylmalonate, diethylphenylmalonate, diethyl diethylmalonate, diethyl dibutylmalonate,monooctyl maleate, dioctyl maleate, dibutyl maleate, dibutylbutylmaleate, diethyl butylmaleate, diisopropyl β-methylglutarate,diallyl ethylsuccinate, di(2-ethylhexyl) fumarate, diethyl itaconate,dioctyl citraconate, diethyl adipate, diisopropyl adipate, diisopropylsebacate, di(n-butyl) sebacate, di(n-octyl) sebacate anddi(2-ethylhexyl) sebacate.

The alicyclic polybasic carboxylic acid ester includes, for example,1,2-cyclohexanedicarboxylic acid diethyl ester,1,2-cyclohexanedicarboxylic acid diisobutyl ester, tetrahydrophthalicacid diethyl ester and nagic acid diethyl ester.

The aromatic polybasic carboxylic acid ester includes, for example,monoethyl phthalate, dimethyl phthalate, methylethyl phthalate,monoisobutyl phthalate, diethyl phthalate, ethylisobutyl phthalate,di(n-propyl) phthalate, diisopropyl phthalate, di(n-butyl) phthalate,diisobutyl phthalate, di(n-heptyl) phthalate, di(2-ethylhexyl)phthalate, di(n-octyl) phthalate, dineopentyl) phthalate, didecylphthalate, benzylbutyl phthalate, diphenyl phthalate, diethylnaphthalenedicarboxylate, dibutyl naphthalenedicarboxylate, triethyltrimellitate or dibutyl trimellitate.

According to the invention, as the polybasic carboxylic acid ester, anaromatic ortho-dicarboxylic acid monoester or diester which has theformula (I):

wherein Ar is a divalent aromatic hydrocarbon group of 6-14 carbons; Ris a monovalent hydrocarbon group of 1-20 carbons; and R′ is a hydrogenor a monovalent hydrocarbon group of 1-20 carbons, is in particularpreferred, which will be for simplicity referred to as the aromaticdicarboxylic acid esters herein after.

In the above formula, Ar is preferably phenylene or naphthylene whichmay carry thereon alkyl substituents. When R and R′ are hydrocarbongroups, they may be the same or different from each other. Thehydrocarbon group includes, for example, an alkyl or a cycloalkyl of1-20 carbons, an aryl, an alkyl aryl or an aryl alkyl of 6-20 carbons.

The aromatic dicarboxylic acid ester includes, for example, monoethylphthalate, dimethyl phthalate, methylethyl phthalate, monoisobutylphthalate, diethyl phthalate, ethylisobutyl phthalate, di(n-propyl)phthalate, diisopropyl phthalate, di(n-butyl) phthalate, diisobutylphthalate, di(n-heptyl) phthalate, di(2-ethylhexyl) phthalate,di(n-octyl) phthalate, dineopentyl phthalate, didecyl phthalate,benzylbutyl phthalate, diphenyl phthalate, diethylnaphthalenedicarboxylate or dibutyl naphthalenedicarboxylate. Thearomatic dicarboxylic acid ester may be used singly or as a mixture oftwo or more. Among the above exemplified aromatic dicarboxylic acidesters, phthalic acid dialkyl esters are particularly preferred.

(Step (1)—Preparation of Solid Material)

According to the invention, in the step (1), the suspension whichcontains a solid material having the polybasic carboxylic acid estersupported thereon may be prepared either by contacting the magnesiumcompound with the first titanium compound in the presence of thepolybasic carboxylic acid ester, or by contacting the magnesium comoundwith the first titanium compound, and then contacting the resultingsolid product with the polybasic carboxylic acid ester, the latter beingpreferred. The contact of the magnesium comound with the first titaniumcompound in the step (1) may be often referred to as the firsttitanation hereinafter.

Further according to the invention, it is in particular preferred that asolution of the magnesium compound is contacted with the first titaniumcompound in the presence of the electron donor to carry out the firsttitanation thereby to form a solid product, and the solid product isthen contacted with the polybasic carboxylic acid ester to support theester on the solid product thereby to form a suspension which containsthe resultant solid material. The preparation of the suspension whichcontains the solid material in this manner provides a solid titaniumcatalyst component which is uniform in shape and particle size.Alternatively, as set forth hereinbefore, such a suspension whichcontains the solid material may be prepared by contacting the magnesiumcomound with the first titanium compound in the presence of thepolybasic carboxylic acid ester. The preparation of the suspension whichcontains the solid material in this manner also provides a solidtitanium catalyst component which is uniform in shape and particle size.

According to the invention, there are further processes for preparingthe suspension which contains the solid material on which a polybasiccarboxylic acid ester is supported.

(1) There is prepared a suspension of a dialkoxymagnesium represented bythe formula:

Mg(OR¹)₂

wherein R¹ is an alkyl of 1-20 carbons, in a hydrocarbon solvent, andthe suspension is contacted with the first titanium compound to providea solid product. While or after the contact, a polybasic carboxylic acidester is supported on the solid product.

(2) There is prepared a solution of an organic magnesium compoundrepresented by the formula:

M_(g)R²R³

wherein R² and R³ are independently an alkyl of 1-20 carbons, and thesolution is contacted with the first titanium compound to provide asolid product. While or after the contact, a polybasic carboxylic acidester is supported on the solid product.

(3) There is prepared a suspension of solid complexes of a halogenatedmagnesium compound with an aliphatic lower alcohol of five carbons orless in a hydrocarbon solvent in the presence of a surfactant. Thesuspension is then cooled to provide a solid product. While or after thecooling, a polybasic carboxylic acid ester is supported on the solidproduct.

According to the invention, the suspension which contains the solidmaterial having the polybasic carboxylic acid ester supported thereonmay be prepared in the presence of a porous carrier material so that theresulting solid material is supported on the porous carrier material.

The porous carrier material usable includes, for example, inorganicoxides such as alumina, silica, boron oxide, magnesium oxide, calciumoxide, titanium oxide, zinc oxide, tin oxide, barium oxide or thoriumoxide, and resins such as a styrene-divinylbenzene copolymer resin.Among these carrier materials, alumina, silica or astyrene-divinylbenzene copolymer resin is preferred.

The temperature at which the magnesium comound is contacted with thefirst titanium compound and the polybasic carboxylic acid ester is thensupported thereon to form the suspension which contains the solidmaterial, or the magnesium compound is contacted with the first titaniumcompound in presence of the polybasic carboxylic acid ester to form thesuspension which contains the solid material, is usually in the range of−70° C. to 200° C. , preferably in the range of −50° C. to 150° C., mostpreferably in the range of −30° C. to 130° C.

The polybasic carboxylic acid ester is supported on the solid productprepared from the magnesium comound and the first titanium compoundusually in an amount of 0.01-5 mole parts, preferably in an amount of0.02-0.5 mole parts, per mole part of the magnesium compound used.

(Step (2))

In the step (2), the solid material is separated from the suspensionprepared in the step (1) and the solid material is supplied to the step(3). According to the invention, while the solid material is separatedfrom the suspension and the solid material is supplied to the step (3),the solid material is maintained at a temperature in the range of70-130° C., preferably in the range of 75-125° C.

More specifically, as illustrated in FIG. 2, as the step (1), thesuspension is prepared in a first reactor 1, and after the reaction, asthe step (2), the suspension is supplied to a first filter 2 through afirst pipe A where the solid material is separated from the suspensionby filtration. The resulting solid material is then supplied to a secondreactor 3 through a second pipe B where the solid material is contactedwith a second titanium as the step (3) which will be set forth in detailhereinafter. The contact of the solid material with the second titaniumcompound in the step (3) may be often referred to as the secondtitanation hereinafter. The step (1) to the step (3) via the step (2) iscarried out in this manner.

The solid material is contacted with the second titanium compound in thesecond reactor 3 to carry out the second titanation to provide asuspension as set forth above, and the suspension is then supplied to asecond filter 4 through a third pipe C where the solid material isseparated. The solid material is then supplied to a washing apparatus 5through a pipe D where the solid material is washed with, for example, ahydrocarbon such as hexane repeatedly until no titanium is detected inthe washing. The solid material is finally supplied to a dryingapparatus 6 through a pipe E where the solid material is dried therebyproviding the solid titanium catalyst component of the invention.

When the step (1), step (2) and step (3) are carried out in a manner asabove, all the first pipe A, the first filter 2 and the second pipe Bshould be maintained at a temperature in the range of 70-130° C. so thatthe solid material is maintained at the temperature according to theinvention.

When the suspension which contains the solid material is supplied fromthe first reactor 1 to the first filter 2 through the first pipe A toseparate the solid material from the suspension, the liquid may bedecanted from the suspension and the residual may be supplied to thefirst filter 2, if necessary.

If necessary, the second titanation may be repeated. In particular, whena magnesium compound is used in the form of suspension in the step (1),it is preferred that the second titanation is repeated. By way ofexample, as illustrated in FIG. 2, after the second titanation iscarried out in the second reactor 3, the resultant suspension is againsupplied to the first filter 2 through the pipe B′ where the solidmaterial is separated from the suspension by filtration, and the solidmaterial is then again supplied to the second reactor 3 through the pipeB where the solid material is contacted with the second titaniumcompound to carry out the second titanation again. When the secondtitanation is repeated in this manner, the pipe B′ and the solidmaterial therein should be maintained at the temperature in the rangehereinbefore defined as well.

The second titanation may be repeated in another manner. Although notshown in the drawing, a further filter is provided in addition to thefirst filter 2 to which the suspension is supplied from the first filter2, and the suspension is filtrated with the further filter, and theresulting solid material is then supplied to the second reactor 3through a further pipe. When the second titanation is repeated in thismanner, the solid material should be maintained at the temperature inthe range hereinbefore defined within the further pipe.

As set forth in detail as above, while the solid material is separatedfrom the suspension in the step (2) and the solid material is suppliedto the step (3), the solid material is maintained at the temperature asherein-before defined. This makes it possible to provide a solidtitanium catalyst component which in turn forms an olefin polymerizationcatalyst which makes it possible to produce polyolefins with a reducedamount of finely divided polymer powder.

The solid material separated from the suspension in the step (2) may bewashed with a hydrocarbon solvent, if necessary, before it is suppliedto the step (3). The hydrocarbon solvent usable may be the same as thehydrocarbon solvents which are used as a diluent for the first titaniumcompound. In particular, aliphatic hydrocarbon solvents such as hexane,heptane or decane, or aromatic hydrocarbon solvents such as toluene orxylene are preferred. Furthermoe, when the solid material separated fromthe suspension in the step (2) is supplied to the step (3), a smallamount of a titanium compound, which may be the same as either the firstor the second, may be added to the solid material.

The infrared absorption specrum of the solid material which is producedin the step (1) in an industrial scale as exemplified in examples whichwill be hereinafter described shows an absorption peak which, however,is not found in the infrared absorption specrum of the solid materialprepared in a laboratory scale. On the other hand, the reaction oftitanium tetrachloride with diisobutyl phthalate at a temperature of notmore than 70° C. provides a solid product which has the same infraredabsorption peak as above. Accordingly, it is likely that while the solidmaterial is separated from the suspension in the step (2) and the solidmaterial is supplied to the step (3), if the solid material is placed ata temperature not more than 70° C., undesirable reactions take placebetween the titanium compound and the polybasic carboxylic acid ester,adversely affecting the finally obtained solid titanium catalystcomponent. It is also found, as seen in Reference Examples 2 and 4 whichwill be described hereinafter, that when the solid material prepared inthe step (1) is placed at a temperature of more than 135 C, the finallyobtained solid titanium catalyst component has a tendency to support asmaller amount of titanium thereon.

(Step (3)—Preparation of Solid Titanium Catalyst Component)

According to the invention, the solid material prepared in the step (2)is contacted with a second titanium compound in the step (3) underheating. The second titanium compound may be the same as or differentfrom the first titanium compound used in the step (1) if it is per seliquid at normal temperatures. As in the case with the first titaniumcompound, the second titanium compound is preferably a titaniumtetrachloride, and most preferably it is titanium tetrachloride. Thecontact of the solid material with the second titanium compound may becarried out in the presence of such a hydrocarbon solvent as isexemplified as the diluent for the first titanium compound.

In the step (3), the second titanium compound is used in an amount of5-200 mole parts, preferably 10-100 mole parts, per mole part of themagnesium compound used.

The solid material is contacted with the second titanium compoundusually at a temperature of 40-200° C., preferably 50-180° C., morepreferably 60-160° C., for a period of one minute to 10 hours,preferably 10 minutes to 5 hours. It is believed that the reaction ofthe solid material with the second titanium compound under heating formsa solid titanium catalyst component of the invention.

After the solid material is contacted with the second titanium compoundfor a time as mentioned, the resulting solid titanium catalyst componentis recovered from the suspension by filtration. It is desirable that thethus recovered solid titanium catalyst component is washed with ahydrocarbon solvent such as hexane repeatedly until no free titanium isdetected from the washing.

The thus obtained solid titanium catalyst component of the inventioncontains magnesium, titanium, halogen atoms and the polybasic carboxylicacid ester, and in addition, the electron donor if it has been used.

According to the invention, the solid titanium catalyst componentcontains magnesium in an amount of 5-35% by weight, preferably 8-30% byweight, more preferably 10-28% by weight, most preferably 12-25% byweight; titanium in an amount of 0.3-10% by weight, preferably 0.5-8% byweight, more preferably 0.8-6% by weight, most preferably 1-5% byweight; halogen atoms in an amount of 30-75% by weight, preferably35-75% by weight, more preferably 38-72% by weight, most preferably40-70% by weight; and the polybasic carboxylic acid ester, and if used,the electron donor, in an amount of 0.5-30% by weight, preferably 1-27%by weight, more preferably 3-25% by weight, most preferably 5-23% byweight.

Further according to the invention, the solid titanium catalystcomponent has a halogen/titanium (atomic ratio) usually of 2-200,preferably 4-90; a magnesium/titanium (atomic ratio) usually of 1-100,preferably 2-50; and an electron donor/titanium (molar ratio) usually of0.01-100, preferably 0.05-50.

The solid titanium catalyst component as defined as above mentioned,when it is used as a component of an olefin polymerization catalyst,provides polyolefins in high yields, and in addition, when it is used asa polymerization catalyst for alpha-olefins having at least three carbonatoms, it provides highly stereospecific polyolefins in high yields witha reduced amount of finely divided polymer powder (for example, having aparticle size of not more than 100 micron meters).

(Preparation of Olefin Polymerization Catalyst)

The olefin polymerization catalyst of the invention comprises the solidtitanium catalyst component, an organometallic compound and a silanecompound having Si—O—C bond in the molecule. The organometallic compoundusable preferably contains a metal of the group I, II or III of theperiodic table. More specifically, the organometallic compound includes,for example, organoaluminum compounds, complex alkylated compounds ofaluminum with one of the group I metals, or organometallic compounds ofthe group II metals. (Preparation of olefin polymerization catalyst -organoaluminum compounds) One of the organoaluminum compounds usablepreferably has the formula:

R^(a) _(n)AlX_(3-n)

wherein R^(a) is a hydrocarbon group of 1-12 carbons; X is a halogenatom or hydrogen atom; and n is a numeral in the range of 1-3.

The hydrocarbon group R^(a) is preferably an alkyl, a cycloalkyl or anaryl of 1-12 carbons, and is exemplified by methyl, ethyl, n-propyl,isopropyl, isobutyl, pentyl, hexyl, octyl, cyclopentyl, cyclohexyl,phenyl or tolyl.

Examples of preferred organoaluminum compounds are trialkyl aluminumssuch as trimethylaluminum, triethylaluminum,triisopropylaluminum,triisobutylaluminum, trioctylaluminum ortri(2-ethylhexyl)aluminum; alkenyl aluminums such as isoprenylaluminum;dialkyl aluminum halides such as dimethylaluminum chloride,diethylaluminum chloride, diisopropylaluminum chloride,diisobutylaluminum chloride or dimethylaluminum bromide; alkyl aluminumsesquihalides such as methylaluminum sesquichloride, ethylaluminumsesquichloride, isopropylaluminum sesquichloride, butylaluminumsesquichloride or ethylaluminum sesquibromide; alkyl aluminum dihalidessuch as methylaluminum dichloride, ethylaluminum dichloride,isopropylaluminum dichloride or ethylaluminum dibromide; alkyl aluminumhydrides such as diethylaluminum hydride or diisobutylaluminum hydride.

Another organoaluminum compounds usable has the formula:

R^(a) _(n)AlY_(3-n)

wherein R^(a) is the same as above mentioned; Y is —OR^(b) group,—OSiR^(c) ₃ group, —OAlR^(d) _(z) group, —NR^(e) _(z) group, —SiR^(f) ₃group or —N(R⁹)AlR^(h) ₂ group: n is a numeral of 1-2; R^(b), R^(c),R^(d) and R^(h) are independently methyl, ethyl, isopropyl, isobutyl,cyclohexyl or phenyl, for example; R^(e) is hydrogen, methyl, ethyl,isopropyl, phenyl or trimethylsillyl, for example; and R^(f) and R^(g)are indeoendently methtyl or ethyl, for example.

Accordingly, these organoaluminum compounds may be exemplified by, forexample:

(i) R^(a) _(n)Al(OR^(b)) _(3-n) such as dimethylaluminum methoxide,diethylaluminum ethoxide or diisobutylaluminum methoxide;

(ii) R^(a) _(n)Al(OSiR^(c))_(3-n) such as Et_(z)Al(OSiMe₃),(iso-Bu)₂Al(OSiMe₃) or (iso-Bu)_(z)Al(OSiEt₃);

(iii) R^(a) _(n)Al(OAlR^(d) _(z))_(3-n) such as Et₂AlOAlEt_(z) or(iso-Bu)_(z)AlOAl(iso-Bu)₂;

(iv) R^(a) _(n)Al(NR^(e) ₂)_(3-n) such as Me₂AlNEt₂, Et₂AlNHMe,Me₂AlNHEt, Et₂AlN(Me₃Si)₂ or (iso-Bu)₂AlN(Me₃Si)₂;

(v) R^(a) _(n)Al(SiR^(f) ₃)_(3-n) such as (iso-Bu)₂AlSiMe₃;

(vi) R^(a) _(n)Al[N(R⁹)—AlR^(h) ₂]_(3-n) such as Et₂AlN(Me)—AlEt₂ or(iso-Bu)₂AlN(Et)Al(iso-Bu)₂.

As further examples of organoaluminum compounds usable, there may bementioned such organoaluminum compounds as have two or more aluminumatoms connected with each other by oxygen or nitrogen atoms. Examples ofsuch organoaluminum compounds are (C₂H₅)₂AlOAl(C₂H₅)₂,(C₄H₉)₂AlOAl(C₄H₉)₂ or (C₂H₅)₂AlNAl(C₂H₅)Al(C₂H₅)₂. Aluminoxanes such asmethylaluminoxane may also be used as an organoaluminum compound.

Among the above mentioned, organoaluminum compounds having the formulaR^(a) ₃Al, R^(a) _(n)Al(OR^(b))_(3-n) or R^(a) _(n)Al(OAlR^(d) ₂)_(3-n)are particularly preferred.

The complex alkylated compound of aluminum with a group I metal has theformula:

M¹AlR^(j) ₄

wherein M¹ is Li, Na or K; R^(j) is a hydrocarbon group of 1-15 carbons.The complex alkylated compound is exemplified by LiAl(C₂H₅)₄ orLiAl(C₇H₁₅)₄, for example.

The organometallic compound of a group II metal has the formula:

R^(k)R^(L)M²

wherein R^(k) and R^(L) are independently a hydrocarbon group of 1-15carbons or a halogen atom; R^(k) and R^(L) may be the same or differentfrom each other; however, both are not halogen atoms at the same time;M² is Mg, Zn or Cd.

The organometallic compound of a group II metal may be exemplified by,for example, diethylzinc, diethylmagnesium, butylethylmagnesium,ethylmagnesium chloride or butylmagnesium chloride.

The organometallic compound may be used singly or as a mixture of two ormore.

(Preparation of Olefin Polymerization Catalyst—Silane Compounds)

The olefin polymerization catalyst of the invention is prepared from thesolid titanium catalyst component, the organometallic compound, bothalready described hereinbefore, and a silane compound having Si—O—C bondin the molecule.

The silane compound usable has preferably the formula:

R_(n)Si(OR′)_(4-n)

wherein R and R′ are independently a hydrocarbon group having 1-20carbons which may carry halogen atoms as substituents thereon; and n isan integer of 0-4.

Accordingly, the silane compound includes, for example,trimethylmethoxysilane, trimethylethoxysilane,tricyclopentylmethoxysilane, tricyclopentylethoxysilane,dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane,dicyclopentylmethylethoxysilane, cyclopentyldimethylmethoxysilane,cyclopentyldiethylmethoxysilane, cyclopentyldimethylethoxysilane,dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane,cyclohexylmethyldiethoxysi lane, dicyclopentyldimethoxysi lane,bis(2-methylcyclopentyl)dimethoxysilane,bis(2,3-dimethylcyclopentyl)dimethoxysilane, dicyclopentyldiethoxysilane, dimethyldimethoxysi lane, dimethyldiethoxysilane,diisopropyldimethoxysilane, t-butylmethyldimethoxysilane,t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane,diphenyldimethoxysilane, phenylmethyldimethoxysi lane,diphenyldiethoxysi lane, bis(o-tolyl)dimethoxysilane,bis(m-tolyl)dimethoxysilane, bis(p-tolyl)dimethoxysilane,bis(p-tolyl)diethoxysilane, bis(ethylphenyl)dimethoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane,methyltrimethoxysilane, n-prop yltriethoxysilane, decyltrimethoxysilane,decyltriethoxysilane, phenyltrimethoxysilane,γ-chloropropyltrimethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane,n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxysilane,γ-aminopropyltriethoxysilane, chlorotriethoxysilane,ethyltriisopropxysilane, vinyltributoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane,2-norbornanemethyldimethoxysilane, trimethylphenoxysilane,methyltriallyloxysilane, vnyltris(β-methoxyethoxy)silane,vinyltriacetoxysilane, cyclopentyltrimethoxysilane,2-methylcyclopentyltrimethoxysilane,2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane orhexenyltrimethoxysilane.

Among the above silane compounds, there are in particular preferredcyclohexylmethyldimethoxysilane, ethyltriethoxysilane,n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane,phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysi lane,phenylmethyldimethoxysi lane, bis(p-tolyl)dimethoxysilane,p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane,2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane,phenyltriethoxysilane, dicyclopentyldimethoxysilane,hexenyltrimethoxysilane, cyclopentyltriethoxysilane,tricyclopentylmethoxysilane or cyclopentyldimethylmethoxysilane.

(Preparation of Olefin Polymerization Catalyst)

The olefin polymerization catalyst of the invention comprises:

(A) the solid titanium catalyst component as prepared as mentionedabove;

(B) the organometallic compound as mentioned as above; and

(C) the silane compound having Si—O—C bond in the molecule as mentionedabove.

The organometallic compund (B) is used in terms of metal contained inthe compound usually in an amount of about 1-2000 mole parts, preferablyabout 2-500 mole parts, per mole part of titanium atom in the solidtitanium catalyst component. The silane compound (C) is used usually inan amount of about 0.001-10 mole parts, preferably about 0.01-5 moleparts, per mole part of the metal atom of the organometallic compound.

For the polymerization of olefins, the solid titanium catalyst component(A) is used in terms of titanium atom usually in an amount of about0.001-100 millimole parts, preferably about 0.05-20 millimole parts, perliter of reaction volume of reactor.

The olefin polymerization catalyst of the invention is advantageouslyused for the (co)polymerization of ethylene and alpha-olefins such aspropylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene,3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene,4,4-dimethyl-1- pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,4-ethyl- 1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene or 1-eicosene. Besides theabove, the olefin polymerization catalyst is used for polymerization ofother vinyl compounds. The vinyl compound includes, for example,cycloolefins such as cyclopentene, cyclobeptene, norbornene,5-ethyl-2-norbornene, tetracyclododecene or2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene; andvinyl compounds such as styrene, dimethylstyrenes, allylnaphthalenes,allylnorbornanes, vinylnaphthalenes, allyltoluenes, allylbenzene,vinylcyclopentane, vinylcyclohexane, vinylcycloheptane orallyltrialkylsilanes.

However, the olefin polymerization catalyst of the invention isparticularly useful for the polymerization of ethylene, propylene,1-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene,vinylcyclohexane, dimethylstyrenes, allyltrialkylsilanes orallylnaphthalenes.

(Process for Polymerization of Olefins)

The process for the polymerization of olefins according to the inventioncomprises polymerizing an olefin or copolymerizing two or more olefinsin the presence of the olefin polymerization catalyst as mentioned abovewhich comprises the solid titanium catalyst component, theorganometallic compound and the silane compound having Si—O—C bond inthe molecule.

A small amount of diene compounds may be copolymerized with the olefinsas above mentioned. The diene compound includes, for example, butadiene,isoprene, 1,3-pentadiene, 1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene,1,5-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene,6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6-octadiene,6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene,7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene,6-methyl-1,6-decadiene, 7-methyl-1,6-decadiene,6-methyl-1,6-undecadiene, 1,7-octadiene, 1,9-decadiene,ethylidenenorbornene, vinylnorbornene or dicyclopentadiene.

The polymerization of olefins may be carried out by any process; such asliquid phase polymerization, e.g., solution or suspensionpolymerization, or gas phase polymerization. When the polymerization iscarried out in a slurry, such an inert hydrocarbon solvent as mentioedhereinbefore may be used as a reaction solvent, or an olefin which isliquid at a temperature at which the reaction is carried out may also beused as a reaction solvent.

The resulting polyolefins can be controlled in their molecular weight byusing a molecular weight controlling agent such as hydrogen thereby toprovide polyolefins having high melt indexes.

The polymerization of olefins is carried out usually at a temperature ofabout 20-300° C., preferably at about 50-150° C., usually under apressure of normal to 100 kg/cm², preferably about 2-50 kg/cm², althoughsomewhat depending on the individual olefins used or manners by whicholefins are polymerized. The polymerization of olefins is carried outeither batchwise, semi-batchwise or continuously. If necessary, thepolymerization may be carried out in two or more stages under differentreaction conditions.

The use of a single olefin provides a homopolymer of the olefin, whilethe use of two more olefins provides a random or block copolymer of theolefins.

(Preparation of Preliminary Olefin Polymerization Catalyst)

According to the invention, a preliminary olefin polymerization catalystmay be prepared and then the olefin polymerization catalyst may beprepared therefrom.

The preliminary olefin polymerization catalyst is prepared bypolymerizing an olefin or two or more olefins preliminarily in thepresence of catalyst components comprising:

(A) the solid titanium catalyst component as prepared as mentionedabove;

(B) the organometallic compound as mentioned above; and optionally

(C) the silane compound having Si—O—C bond in the molecule as mentionedabove.

For the preparation of the preliminary olefin polymerization catalyst,any alpha-olefin having at least two carbons may be used with nolimitation. The alpha-olefin usable includes, for example, ethylene,propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene,3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene,4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene or 1-eicosene. Other vinylcompounds or polyene compounds mentioned hereinbefore may be used inplace of the olefins above, or may be preliminarily polymerized togeterwith the olefins above. The olefin, vinyl compound or polyene compoundmay be used singly or as a mixture of two or more. The olefin used inthe preparation of preliminary olefin polymerization catalyst may be thesame as or different from the oefin which is polymerized in a full scalelater.

There is no limitation in the method for preliminary polymerization ofolefins. By way of example, the olefin may be polymerized in the liquidphase, if necessary in the presence of an inert reaction solvent, or inthe gas phase. However, among these methods, it is preferred that thepreliminary polymerization is carried out in an inert reaction solventin the presence of the catalyst components under relatively mildreaction conditions. The resulting polymer thus preliminarilypolymerized may be soluble or not in the solvent, with the latter beingpreferred.

The preliminary polymerization of olefins is carried out eitherbatchwise, semi-batchwise or continuously at a temperature in the rangeof about −20° C. to 100° C., preferably at about −20° C. to 80° C., morepreferably at about −10° C. to 40° C.

In the preliminary polymerization of olefins, the catalyst may be usedin a concentration higher than in the later full scale polymerization.Although depending upon the individual catalyst components used, thesolid titanium catalyst component (A) is used in terms of titanium atomin an amount of about 0.001-5000 millimole parts, preferably about0.01-1000 millimole parts, more preferably about 0.1-500 millimoleparts, per liter of the volume of reactor, while the organometalliccompound (B) is used in such an amount that prelinary (co)polymers areformed usually in an amount of 0.01-2000 g, preferably 0.03-1000 g, morepreferably 0.05-200 g, per gram of the solid titanium catalyst component(A). Accordingly, the organometallic compound (B) is used usually in anamount of about 0.1-1000 mole parts, preferably about 0.5-500 moleparts, more preferably about 1-100 mole parts, per mole part of titaniumof the solid titanium catalyst component.

In the preliminary polymerization of olefins, the silane compound (C)may be used, if necessary, usually in an amount of 0.01-50 mole parts,preferably about 0.05-30 mole parts, more preferably about 0.1-10 moleparts, per mole part of titanium atom of the solid titanium catalystcomponent (A). A molecular weight controlling agent such as hydrogen mayalso be used when the preliminary polymerization of olefins is carriedout.

When the preliminary olefin polymerization catalyst is obtained as aslurry or suspension, the catalyst may be used as it is in a later fullscale polymerization of olefins, or alternatively the catalyst may beseparated from the suspension and then used in the full scalepolymerization.

The preliminary olefin polymerization catalyst is used usually toprepare an olefin polymerization catalyst of the invention incombination with the beforementioned organometallic compound and thesilane compound. However, the preliminary olefin polymerization catalystalone may be used as an olefin polymerization catalyst as the case maybe. When a silane compound has not been used in the preparation ofpreliminary olefin polymerization catalyst, an olefin polymerizationcatalyst of the invention may be prepared from the preliminary olefinpolymerization catalyst and the silane compound.

As set forth above, the solid titanium catalyst component of theinvention provides an olefin polymerization catalyst which has higholefin polymerization activity and provides polyolefins having highstereospecificity and a high bulk density with a reduced amount offinely divided polymer powder produced.

EXAMPLES

The invention will be described with reference to examples, however, theexamples are illustrative only and the invention is not limited thereto.

Example 1

(Preparation of Solid Titanium Catalyst Component (A))

98.5 kg of 2-ethylhexyl alcohol, 78.3 kg of decane and 24 kg of magnsiumchloride were placed in a 0.5 m³ capacity vessel, and the mixture washeated to 140° C. to prepare an even solution. 5.6 kg of phthalicanhydride was added to the solution and stirred under heating to providea colorless and even solution. The solution was then cooled to roomtemperatures to prepare a solution of the magnesium compound.

As shown in FIG. 2, 0.3 m³ of recovered titanium tetrachloride havingthe composition below was placed in a one cubic meter capacity firstreactor 1, and was cooled to −20° C., whereupon 103.2 kg of the solutionof the magnesium compoud was added to the titanium tetrachloride. Therecovered titanium tetrachloride was composed of 95.4% by weight oftitanium tetrachloride, 0.2% by weight of hexane, 2.2% by weight ofoctane, 0.2% by weight of nonane, 1.6% by weight of decane and 0.4% byweight of 2-chlorooctane.

The resulting reaction mixture was heated to 110° C. and 8.8 kg ofdiisobutyl phthalate was added to the mixture followed by stirring fortwo hours at the temperature. The resulting suspension was sent to afirst filter 2 from the first reactor 1 under nitrogen pressure througha first pipe A where the suspension was filtrated to separate theresulting solid material. A small amount of titanium tetrachloride wasadded to the solid material and was then sent to a one cubic metercapacity second reactor 3 under nitrogen pressure through a second pipeB. While these operations were carried out, the solid material in thefirst filter 2 as well as the first pipe A through which the suspensionwas sent to the first filter 2 from the first reactor 1 under pressure,the first filter 2 and the second pipe B were maintained at thetemperature indicated in Table 1.

0.4 m³ of the same recovered titanium tetrachloride as above was addedto the second reactor 3, the mixture was heated to 110° C. andmaintained at the temperature for 20 minutes. The resulting suspensionwas sent to a second filter 4 under nitrogen pressure through a pipe Cwhere the suspension was filtrated to separate the resulting solidmaterial. A small amount of hexane was added to the solid material andthe mixture was supplied to a one cubic meter capacity washing apparatus5 through a pipe D. The solid material was washed three times each with0.4 m³ of hexane at 60° C. and then further washed repeatedly withhexane at normal temperatures until no titanium was detected in thesupernatant. After the washing in ths way, the solid material was sentto a drying apparatus 6 through a pipe E where the solid material wasdried to provide a solid titanium catalyst component of the invention.The composition of the catalyst component is shown in Table 2.

(Polymerization of Propylene)

750 ml of purified hexane was placed in a two liter capacity autoclaveand-then 0.0075 millimole of the solid titanium catalyst component interms of titanium atom together with 0.75 millimole of triethylaluminum,0.075 millimole of cyclohexylmethyldimethoxysilane (CMMS) at atemperature of 40° C. under a propylene atmosphere.

200 ml of hydrogen was then fed into the autoclave at a temperature of60° C., followed by heating to 70° C. and maintaining at the temperaturefor two hours to carry out the polymerization of propylene while thepressure in the autoclave was maintained at 7 kg/cm² G (gage).

After the polymerization, the slurry which contained the resultingpolypropylene was filtrated to separate while powder, followed by dryingunder reduced pressures for ten hours to provide polypropylene. Theresults of polymerization are shown in Table 3.

Examples 2 and 3

(Preparation of Solid Titanium Catalyst Component (A))

The pipe A, the first filter 2, the solid material in the first filter 2and the pipe B were maintained at the temperature indicated in Table 1,and otherwise in the same manner as in EXAMPLE 1, a solid titaniumcatalyst component was prepared. The composition of the catalystcomponent is shown in Table 2.

(Polymerization of Propylene)

The polymerization of propylene was carried out in the same manner as inEXAMPLE 1 except that the above solid titanium catalyst component wasused. The results of polymerization are shown in Table 3.

Reference Examples 1 and 2

(Preparation of Solid Titanium Catalyst Component (A))

The pipe A, the first filter 2, the solid material in the first filter 2and the pipe B were maintained at the temperature indicated in Table 1,and otherwise in the same manner as in EXAMPLE 1, a solid titaniumcatalyst component was prepared. The composition of the catalystcomponent is shown in Table 2.

(Polymerization of Propylene)

The polymerization of propylene was carried out in the same manner as inEXAMPLE 1 except that the above solid titanium catalyst component wasused. The results of polymerization are shown in Table 3.

TABLE 1 Temperaturec (° C.) Examples Reference 1 2 3 1 2 Pipe A  90 10575 60 135 First Reactor 100 105 85 70 135 Solid Material 100 105 85 70135 in First Filter Pipe B  90 105 75 60 135

TABLE 2 Component of Solid Titanium Catalyst Component (% by weight)Examples References 1 2 3 1 2 Ti 2.6 2.3 2.8 3.0 2.5 Cl 60 61 60 60 62Mg 18 19 18 18 19 DIBP¹⁾ 14.5 13.5 14.8 15.4 12.1 OEH²⁾ 0.0 0.0 0.0 0.00.0 Notes: ¹⁾Diisobutyl phthalate ²⁾Ethylhexoxyl group

TABLE 3 Examples Reference Examples 1 2 3 1 2 Activity per 23200 2260020300 19100 10800 Ti (g) Acitivi per 12600 10900 11900 12000 5600Catalyst (g) t-I.I. (%) 98.1 98.2 98.0 98.0 95.4 MFR (g/10 5.8 5.5 5.25.5 7.1 minutes) Bulk Density 0.45 0.45 0.45 0.45 0.43 (g/ml) Melting161.0 161.0 160.8 160.7 158.5 Point (° C.) Fine 0.0 0.1 0.5 2.1 10.3Polymer Powder (% by weight)

In Table 3, t-I.I. represents a total isotactic index and is defined asbelow:${t - {I.I.}} = {\left( {\left\lbrack {{polymer}\quad {powder}\quad (g) \times \left( \frac{\begin{matrix}{{extract}\quad {residue}\quad {by}} \\{{boiling}\quad {hexane}\quad (\%)}\end{matrix}}{100} \right)} \right\rbrack/\left\lbrack \quad {{{polymer}{\quad \quad}{{powder}{\quad \quad}(\quad g)}} + {{solvent}\quad {soluble}\quad {polymer}\quad (g)}} \right\rbrack} \right) \times 100\quad (\%)}$

The activity per Ti is the yield (g) of polypropylene per millimole oftitanium of the solid titanium catalyst component (g-PP/mmol-Ti); theactivity per catalyst is the yield (g) of polypropylene per gram ofpolymerization catalyst (g-PP/g-catalyst); and MFR means melt flow rate.

The fine polymer powder has a particle size of less than 100nicronmeter.

Example 4

(Preparation of Solid Titanium Catalyst Component (A))

As shown in FIG. 2, 40 kg of diethoxymagnesium was placed in a one cubicmeter capacity first reactor 1 together with 0.32 m³ of toluene toprepare a suspension. 80 liters of titanium tetrachloride was added tothe suspension while the suspension was maintained at a temperature of20° C. The suspension was then raised to a temperature of 85° C., and 11liters of diisobutyl phthalate was added, followed by heating to atemperature of 110° C. and maintaining the suspension at the temperaturefor two h hours.

The suspension was sent to a first filter 2 under nitrogen pressurethrough a pipe A to separate a solid material. After the addition of asmall amount of toluene to the solid material, it was filtrated. Thisoperation was repeated five times. A small amount of toluene was addedto the solid material thus obtained, and the solid material was sent toa one cubic meter capacity second reactor 3 under nitrogen pressurethrough a pipe B. 80 liters of titanium tetrachloride and 0.32 m³ oftoluene were placed in the second reactor 3, and the mixture was heatedto a temperature of 110° C. and maintained at the temperature for onehour. While these operations were carried out, the pipe A, the solidmaterial in the pipe A, the first filter 2, the solid material in thefirst filter 2, the solid material in the first filter 2, the pipe B andthe solid material in the pipe B were maintained at the temperatureindicated in Table 4.

The resulting suspension prepared in the second reactor 3 was returnedto the first filter 2 through a pipe B′ where the suspension wasfiltrated to separate a solid material. A small amount of toluene wasadded to the solid material and the solid material was filtrated. Thisoperation was repeated five times. After the addition of a small amountof toluene to the solid material, the solid material was then sent tothe one cubic meter capacity second reactor 3 again under nitrogenpressure through the pipe B. In the same manner as mentionedhereinabove, 80 liters of titanium tetrachloride and 0.32 m³ of toluenewere added to the second reactor 3, and the mixture was heated to atemperature of 110° C. followed by maintaining the mixture at thetemperature for one hour. While these operations were carried out, thepipe B′, the solid material in the pipe B′, the first filter 2, thesolid material in the first filter 2, the pipe B and the solid materialin the pipe B were maintained at the temperature indicated in Table 4.

The suspension thus prepared in the second reactor 3 was sent to asecond reactor 4 under nitrogen pressure through a pipe C where thesuspension was filtrated to separate a solid material. After theaddition of a small amount of hexane to the solid material, the solidmaterial was then sent to a one cubic meter capacity washing apparatus5. The solid material was washed three times each with 0.4 m³ of hexaneat 60° C. and then further washed repeatedly with hexane at normaltemperatures until no titanium was detected in the supernatant. Afterthe washing in ths way, the solid material was sent to a dryingapparatus 6 where the solid material was dried to provide a solidtitanium catalyst component of the invention. The composition of thecatalyst component is shown in Table 5.

(Polymerization of Propylene)

The polymerization of propylene was carried out in the same manner as inEXAMPLE 1 except that the above solid titanium catalyst component wasused. The results of polymerization are shown in Table 6.

Reference Examples 3 and 4

(Preparation of Solid Titanium Catalyst Component (A))

The pipe A, the solid material in the pipe A, the first filter 2, thesolid material in the first filter 2, the pipe B and solid material inthe pipe B were maintained at the temperature indicated in Table 4, andotherwise in the same manner as in EXAMPLE 4, a solid titanium catalystcomponent was prepared. The composition of the catalyst component isshown in Table 5.

(Polymerization of Propylene)

The polymerization of propylene was carried out in the same manner as inEXAMPLE 1 except that the above solid titanium catalyst component wasused. The results of polymerization are shown in Table 6.

TABLE 4 Temperatures (° C.) Example Reference Examples 4 3 4 Pipe A  90 65 115 Solid Material in Pipe A  90  60 115 First Filter 100 100 135Solid Material in First Filter 100 100 135 Pipe B and B‘  90  60 135Solid Material in Pipe B and B‘  90  60 135

TABLE 5 Component of Solid Titanium Catalyst Component (% by weight)Example Reference Examples 4 3 4 Ti 2.8 3.2 2.4 Cl 58 55 56 Mg 18 18 18DIBP¹⁾ 13.1 15.4 11.5 OEH²⁾ 0.0 0.0 0.0 OEt³⁾ 3.5 3.3 2.9 Notes:¹⁾Diisobutyl phthalate ²⁾Ethylhexoxyl group ³⁾Ethoxyl group

TABLE 6 Example Reference Examples 4 3 4 Activity per Ti (g) 31800 2710016400 Acitivi per Catalyst (g) 18600 18100 8200 t-I.I. (%) 96.8 96.795.8 MFR (g/10 minutes) 6.4 7.0 7.2 Bulk Density (g/ml) 0.38 0.36 0.35Melting Point (° C.) 160.7 160.5 159.3 Fine Polymer Powder 2.5 3.9 4.4(% by weight)

Example 5

(Preparation of Solid Titanium Catalyst Component (A))

The atmosphere in a two cubic meter capacity high performance agitatorwas fully replaced with nitrogen. 70 liters of purified kerosene, 10 kgof commercially available magnesium chloride, 24.2 kg of ethanol and 3kg of a surfactant, sorbitan distearate (Emasol 320 available from KaoAtlas K.K.), were placed in the agitator. The resulting mixture washeated to a temperature of 120° C. with stirring and was then stirred ata rate of 800 rpm at the temperature for 30 minutes, thereby providing asuspension which contained particles of complex of magnesium chlorideand ethanol.

The suspension was transferred to a two cubic meter capacity reactorprovided with a stirrer in which a cubic meter of purified kerosene keptat −10° C. had been placed with effective stirring through apolytetrafluoroethylene tube having an inside diameter of 5 mm toprovide solid products. The solid product was fully washed with purifiedkerosene.

As shown in FIG. 2, 0.4 m³ of titanium tetrachloride and 20 kg of thesolid product were placed in a one cubic meter capacity first reactor.The resulting mixture was heated to 120° C. in 2.5 hours. When themixture reached a temperature of 100° C. in the course of the heating,3.6 liters of diisobutyl phthalate was added to the mixture. Thereaction mixture was maintained at 120° C. for 1.5 hours. The resultingsuspension was sent to a first filter 2 from the first reactor 1 undernitrogen pressure through a first pipe A where the suspension wasfiltrated to separate the resulting solid material. A small amount oftitanium tetrachloride was added to the solid material and was then sentto a one cubic meter capacity second reactor 3 under nitrogen pressurethrough a second pipe B. While these operations were carried out, thesolid material in the first filter 2 as well as the first pipe A throughwhich the suspension was sent to the first filter 2 from the firstreactor 1 under pressure, the first filter 2 and the second pipe B weremaintained at the temperature indicated in Table 7.

0.4 m³ of titanium tetrachloride was added to the second reactor 3, themixture was then heated to 130° C. and maintained at the temperature forone hour. The resulting suspension was sent to a second filter 4 undernitrogen pressure through a pipe C where the suspension was filtrated toseparate the resulting solid material. A small amount of hexane wasadded to the solid material and the mixture was supplied to a onecubicmeter capacity washing apparatus 5 through a pipe D. The solidmaterial was washed three times each with 0.4 m³ of hexane at 60° C. andthen further washed repeatedly with hexane at normal temperatures untilno titanium was detected in the supernatant. After the washing in thsway, the solid material was sent to a drying apparatus 6 through a pipeE where the solid material was dried to provide a solid titaniumcatalyst component of the invention. The composition of the catalystcomponent is shown in Table 8.

(Polymerization of Propylene)

The polymerization of propylene was carried out in the same manner as inEXAMPLE 1 except that the above solid titanium catalyst component wasused. The results of polymerization are shown in Table 9.

TABLE 7 Temperatures (° C.) Example Reference 5 5 Pipe A  90  60 SolidMaterial in Pipe A  90  60 First Filter 100 100 Solid Material in FirstFilter 100 100 Pipe B  90  60 Solid Material in Pipe B  90  60

TABLE 8 Component of Solid Titanium Catalyst Component (% by weight)Example Reference Example 5 5 Ti 2.3 2.6 Cl 650 650 Mg 210 210 DIBP¹⁾4.6 5.4 OEH²⁾ 0.0 0.0 Notes: ¹⁾Diisobutyl phthalate ²⁾Ethylhexoxyl group

TABLE 9 Example Reference Example 5 5 Activity per Ti (g) 26600 21900Acitivi per Catalyst (g) 12800 11900 t-I.I. (%) 97.6 97.5 MFR (g/10minutes) 6.1 6.3 Bulk Density (g/ml) 0.46 0.45 Melting Point (° C.)160.7 160.5 Fine Polymer Powder 0.0 1.2 (% by weight)

What is claimed is:
 1. A process for the preparation of a solid titaniumcatalyst component which comprises: (1) a step wherein a suspension isprepared which contains a solid material prepared by contacting amagnesium compound with titanium tetrachloride and having a polybasiccarboxylic acid ester supported on said solid material, wherein saidtitanium tetrachloride is used in an amount of 0.01-1000 mole parts permole part of the magnesium compound used and said polybasic carboxylicacid ester is used in an amount of 0.01-5 mole parts per mole part ofthe magnesium compound used; (2) a step wherein the solid material isseparated from the suspension; and (3) a step wherein the solid materialis contacted with titanium tetrachloride under heating wherein saidtitanium tetrachloride is used in an amount of 5-200 mole parts per molepart of the magnesium compound used; wherein while the solid material isseparated from the suspension in the step (2) and the solid material issupplied to the step (3), the solid material is maintained at atemperature in the range of 70-130° C., said temperature beingmaintained in said range from the end of step 1 to the beginning of step3; and wherein said titanium tetrachloride is liquid at normaltemperature; said magnesium compound is selected from the groupconsisting of magnesium chloride and diethoxymagnesium; and saidpolybasic carboxylic acid ester is a phthalic acid dialkyl ester whereineach of the alkyls have 1-20 carbons and the alkyls may be the same ordifferent from each other.
 2. A process as claimed in claim 1 whereinthe magnesium compound is dissolved in a solvent which is a solubilizingagent.
 3. A process as claimed in claim 2 wherein the solubilizing agentis an aliphatic alcohol of not less than 6 carbons.
 4. A process asclaimed in claim 1 wherein the magnesium compound is dissolved in ahydrocarbon solvent in the presence of an aliphatic alcohol of not lessthan 6 carbons as a solubilizing agent.
 5. A process as claimed in claim2, 3 or 4 wherein the magnesium compound is contacted with titaniumtetrachloride in the presence of an electron donor wherein: the electrondonor is at least one of organic carboxylic acid esters, aliphaticcarboxylic acids, acid anhydrides, ketones, ethers, aliphaticcarbonates, silane compounds or organophosphorus compounds.
 6. A processas claimed in claim 1 wherein the polybasic carboxylic acid ester isdialkyl phthalate.
 7. A solid titanium catalyst component prepared by aprocess as claimed in claim
 1. 8. An olefin polymerization catalystwhich comprises: (A) the solid titanium catalyst component prepared by aprocess as claimed in claims 1; (B) an organometallic compound; and (C)a silane compound having Si—O—C bond in the molecule.
 9. An olefinpolymerization catalyst as claimed in claim 8 therein the silanecompound has the formula of R³ _(n)Si(OR⁴)_(4-n) wherein R³ and R⁴ areindependently monovalent hydrocarbon groups of 1-20 carbons; and n is aninteger of 1-3.
 10. A preliminary olefin polymerization catalyst whichis prepared by preliminarily polymerizing an olefin or copolymerizingtwo or more olefins in the presence of catalyst components comprising:(A) the solid titanium catalyst component prepared by a process asclaimed in claim 1; and (B) an organometallic compound; and optionally(C) a silane compound having Si—O—C bond in the molecule.
 11. Apreliminary olefin polymerization catalyst as claimed in claim 10wherein the silane compound has the formula of R³ _(n)Si(OR⁴)_(4-n)wherein R³ and R⁴ are independently monovalent hydrocarbon groups of1-20 carbons; and n is an integer of 1-3.
 12. A process for polymerizingolefins in the presence of the olefin polymerization catalyst as claimedin claim 8 or
 9. 13. A process for polymerizing olefins in the presenceof the olefin polymerization catalyst which comprises the preliminaryolefin polymerization catalyst as claimed in claim 10 or
 11. 14. Aprocess as claimed in claim 1, wherein the polybasic carboxylic acid isdibutyl phthalate.